A 0.4-V 10.9- $\mu$ W/Pole Third-Order Complex BPF for Low Energy RF Receivers.

This paper presents a 0.4-V ultra-low power (ULP) third-order active-RC complex band-pass filter (CxBPF) for Bluetooth low energy receivers prototyped in a 180 nm CMOS process. The ULP is reached by using single-stage inverter-based operational transconductance amplifiers (OTA) instead of two or more stages OTA. The effects of the low voltage gain and resistive loading are reduced by using a process and temperature robust negative transconductor connected to the virtual ground. The ultra-low voltage operation is reached by using only two stacked transistors and PMOS bulk forward bias. The CxBPF operates well down to 0.4V power supply and the experimental results present power dissipation of only $10.9~\mu \text{W}$ /pole, 1 MHz bandwidth centered at 2 MHz, image rejection rate of 34 dB, and 12.7 fJ FoM. [ABSTRACT FROM AUTHOR]